Totable, spring-biased, toggle-action firearm

ABSTRACT

A hyper velocity firearm has a downwardly-hinging toggle action. The toggle action incorporates at least one coiled torsion spring that is incorporated in at least one pivot of the toggle. A first embodiment of the firearm employs two torsion springs. A second embodiment employs a single adjustable-tension torsion spring. Tension is adjustable without disassembly of the toggle mechanism. A third embodiment employs a horizontally-oriented compressible coil spring positioned above the toggle to bias the toggle. In the pre-discharge configuration, the toggle of the present invention is about 3 degrees from a straight angle linkage, with a negative degree angle representing an over-center condition. The toggle action is compact and reduces recoil and muzzle lift when the firearm is discharged.

This application for patent has a priority based on the filing of provisional patent application No. 60/765,791 is related to copending application No. 60/765,791, titled TOTABLE, TORSION-SPRING-BIASED-TOGGLE-ACTION FIREARM FOR LAUNCHING HYPERVELOCITY PROJECTILES, which was filed on Feb. 7, 2006.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates generally to firearms and, more particularly, to handguns and rifles having toggle-actions which facilitate the loading of cartridges and ejecting of spent cartridge casings, and which reduce recoil and barrel lift.

2. History of the Prior Art

Small arms which could be fired repeatedly without reloading after each shot were the focus of many inventions since the dawn of firearms. While a number of repeating firearms had already been developed by the turn of the 19^(th) century, none of them had achieved any degree of commercial success, primarily because they were too complicated and cumbersome. It was modern cartridge ammunition that made repeating firearms practical.

In 1830, while a 16-year-old hired hand on a merchant ship bound for India, Samuel Colt developed a simple revolving ammunition cylinder for firearms in his spare time. By 1856, Colt's company was enjoying phenomenal success, with the manufacture of 150 revolver handguns a day. A rifle revolver was also produced in limited numbers. The extremely simple, highly reliable weapon had a profound effect on life in the United States and later in the rest of the world. As anyone packing a revolver could kill another almost instantly, war, crime, and law enforcement were forever altered. Even arguments became hazardous.

Christopher Spencer is generally credited with the manufacture of the first practical non-revolver repeating rifle. Model 1863, 1865 and M-1865 Spencer rifles, which were supplied to the Union forces under Federal Government contract, use a long blade on the left of the breech block carrier. In the M-1865 model, the blade is held forward with a helper spring to make single cartridge loading easier. Although Spencer rifles and carbines are credited as having turned the tide of several Civil War battles, the Henry sporting rifle of the same period was a superior firearm.

The ancestor of the Henry and Winchester rifles was the Volcanic lever action rifle designed by Horace Smith and Daniel B. Wesson. It was originally manufactured by the Volcanic Repeating Arms Company, which was later reorganized into the New Haven Arms Company, of which Oliver Winchester was the major stockholder. The Volcanic rifle used a form of “caseless” ammunition and had only limited success. Wesson had also designed an early form of rimfire cartridge which was subsequently perfected by Benjamin Tyler Henry. Henry also supervised the redesign of the Volcanic rifle to use the new ammunition, retaining only the general form of the breech mechanism and the tubular magazine. This became the Henry rifle of 1860, which was manufactured by the New Haven Arms Company and was used in considerable numbers by certain Union Army units in the Civil War. As the New haven Arms Company received no Union contracts, the Henry rifles were purchased by individual soldiers or with state funding. After the New Haven Arms Company was purchased by Oliver Winchester, the Henry rifle became the basis for the design of the famous Winchester Model 1873, 1876 and 1886 rifles. In this type of lever action rifle, rounds are individually loaded into a tubular chamber parallel to and below the barrel. A short bolt is held in place with an over-center toggle action. Once closed the over center action prevents opening solely by the force on the bolt when the weapon is fired. This toggle action is operated by a hand grip, or lever, that forms part of the trigger guard. When operated, a spring in the tubular magazine pushes a fresh round into position. Returning the operating lever to the home position chambers the round and closes the breach. An interlock prevents firing unless the toggle is fully closed.

In 1893, Hugo Borchardt, a naturalized U.S. citizen born in Germany, developed the C93 semiautomatic pistol for the Ludwig Lowe Company in Karlsruhe. It combined elements of Hiram Percy Maxim's 1884 machine gun and the toggle lever action of the Henry and Winchester rifles. Borchardt reversed the toggle action and reduced its size so that the toggle opened upwards, thereby providing space for an ammunition magazine in the pistol grip. Although a fine target pistol, the Borchardt was somewhat fragile. A bulky protrusion behind the grip, which housed the mainspring and toggle mechanism, also made the Borchardt rather cumbersome. As a result of those deficiencies, it was never a commercial success.

A colleague of Hugo Borchardt, named Georg Luger, redesigned the Borchardt handgun, making it lighter, far more compact, and more reliable. The design, which is instantly recognizable for its clean flowing lines, tapered barrel, and a magazine-containing grip that is acutely angled to the barrel centerline, remained a staple of the German military up until the adoption of the Walther P38 in 1942.

Both the Borchardt and Luger are locked-breech, magazine-fed, semi-automatic pistols that use the same unique toggle action to lock the breech momentarily during firing. The toggle action moves to the rear for a short distance with the barrel and then pivots upwards once chamber pressures have reached a safe level to unlock the action, cock the firing mechanism and eject the spent cartridge case. On its forward movement, the lock pivots down to strip a fresh round from the magazine, load the round into the chamber, and lock the breech. In addition to performing the functions related to semiautomatic operation, the toggle action has the added advantage of reducing recoil when fired. A disadvantage of the Borchardt and Luger designs is that the upward opening of the toggle increases the tendency of the front of the gun to rotate (i.e., lift, with respect to the rear, when fired).

U.S. Pat. No. 4,183,282 to Walter E. Perrine discloses a toggle action pistol in which the toggle mechanism pivots in a downward direction. The Perrine pistol is not as compact as the Luger, due to the fact that a coil mainspring is located in the hand grip, and the ammunition magazine must, consequently, be positioned in front of the trigger assembly. However, it does have an advantage in that the gun tends to remain more nearly level when fired, as the downward toggle action tends to lift the rear of the gun at the same time that the front of the gun is lifting as a consequence of the gun being held behind the barrel and below the barrel centerline. The bulkiness of the Perrine pistol most likely contributed to its failure in the marketplace.

What is needed is a downward toggling firearm which eliminates the bulkiness of the Perrine design, yet retains the excellent potential for rearward and rotational recoil reduction.

SUMMARY OF THE INVENTION

The toggle action firearm that is the focus of the present application is part of hypervelocity weapon system that also includes a cartridge casing having a primer system that is as strong as the cartridge casing, itself. Because blowout or blow-through of conventional primer cups is eliminated by the new design, ultra-high-energy charges can be used that can provide greatly enhanced muzzle velocities. The new primer system eliminates the thin-gauge metal of conventional primer cups by utilizing a primer striker, which acts as a firing pin internal to the cartridge, itself. The primer striker, which is retained in the cartridge casing by an annular shoulder at the end of a cylindrical seat within which the primer striker slides, has a forward facing nipple which dents the face of a primer cup installed inside the cartridge. The primer cup is installed within a primer carrier, and a compressible, centrally-perforated, resilient rubber wafer is positioned between the primer striker and the primer cup, thereby preventing accidental ignition of the charge caused by unintended, minor impacts to the exposed primer striker. The rubber wafer also seals the primer and propellant charges against moisture. The hypervelocity weapon system also includes a blunt-ended ramrod, which replaces the conventional firing pin. The blunt end is sized so that it can enter the aperture at the center of the annular shoulder, thereby displacing the primer striker.

The toggle action firearm of the present invention is envisioned as a hypervelocity sniper rifle, which is easily totable by a single average soldier, and which has the capability to fire 0.50 caliber rounds powered by ultra-high-energy charges with minimum recoil. It is envisioned that the weapon system can produce muzzle velocities in excess of 5,000 ft/sec. The rifle may be configured as a single-shot, semi-automatic, or fully automatic firearm. Like the toggle of Perrine, the toggle of the present invention is downward hinging. However, in place of the bulky coil spring of Perrine, the toggle action of the present invention utilizes at least one coiled torsion spring that is incorporated in at least one pivot of the toggle. For one embodiment of the rifle, a single adjustable-tension torsion spring is employed. Tension is adjustable without disassembly of the toggle mechanism. Unlike the Winchester toggle action, the action of the present invention, as well as those of Borchardt, Luger, and Perrine, dispense with the over center lock feature so that the toggle can be used to implement an automatic load and eject function. In the pre-discharge configuration, the toggle of the present invention is about 3 degrees from a straight angle linkage, with a negative degree angle representing an over-center condition.

BRIEF DESCRIPTION OF THE DRAWING

FIGS. 1A, 1B and 1C are prior art exploded diagrams of an AR-15 rifle;

FIG. 2 is a cross-sectional view of a new first embodiment spring-biased, toggle-action rifle, taken through a plane passing through the centerline of the barrel and receiver, and through the centerline of the handle, showing the toggle action in a pre-discharge configuration;

FIG. 3 is a cross-sectional view of the rifle of FIG. 1, taken through the same plane, but showing the toggle action in a post-discharge configuration;

FIG. 4 is a side elevational view of the rifle of FIG. 1, with the stock cut away to show the toggle action in a post-discharge configuration;

FIG. 5 is an isometric view of the rifle of FIG. 1, with the stock removed, and showing the toggle action in a post-discharge configuration;

FIG. 6 is a cross-sectional view of a new second embodiment spring-biased, toggle-action rifle, taken through a plane passing through the centerline of the barrel and receiver, and through the centerline of the handle, showing the toggle action in a post-discharge configuration;

FIG. 7 is an isometric view of the rifle of FIG. 5, with the stock removed, and showing the toggle action in a post-discharge configuration;

FIG. 8 is a cross-sectional view of a third embodiment spring-biased, toggle-action rifle before firing, the third embodiment rifle having a compressible coil spring in place of at least one torsion spring;

FIG. 9 is an isometric cut-away view of the third embodiment spring-biased, toggle-action rifle of FIG. 8 after firing;

FIG. 10 is a cross-sectional view of the third embodiment spring-biased, toggle-action rifle of FIG. 8 after firing;

FIG. 11 is an elevational see-through view of the third embodiment spring-biased, toggle-action rifle of FIG. 8 after firing;

FIG. 12 is an isometric see-through view of the third embodiment spring-biased, toggle-action rifle of FIG. 8 after firing;

FIG. 13 is a side elevational view of an exemplary ramrod which can be used in the rifle to fire the new cartridge; and

FIG. 14 is an isometric view of the ramrod of FIG. 13.

DETAILED DISCLOSURE OF THE INVENTION

The various embodiments of the invention will now be explained in detail with reference to the attached drawing figures. In order to demonstrate the functionality of the present invention, the various embodiments have been incorporated into a gas-operated AR15 rifle, which is essentially a semi-automatic commercial version of the M16 U.S. military rifle. Some versions of the M16 can be fired in a fully automatic mode for short bursts. With some additional machining of the AR-15 receiver, and replacement of the AR-15 fire control components—including the sear and bolt carrier—with corresponding automatic M16 components, the AR-15 can be converted to fully automatic. An exploded diagram of a typical AR-15 rifle is shown in FIG. 1. It will be subsequently noted that at least the following components of FIG. 1 are either eliminated, replaced with a new component, or extensively modified in order to implement the present invention: the receiver extension, the buttstock, the buttcap spacer, the action spring, and the buffer assembly.

Referring now to FIGS. 2, 3 and 4, a first embodiment 200 of the new hypervelocity rifle has an action tube 201 that is attached to the upper receiver 202. It will be noted that the action tube 201, which has replaced the receiver extension of the AR-15 rifle of FIG. 1, includes a lower longitudinal slot 203, through which the toggle 204 consisting of a front link 205 and a rear link 206 can hinge in a downward direction. The rear end 207 of a bolt carrier 208 is in contact with a forward end 209 of an action guide 210, which slides back and forth within the action tube 201. The bolt carrier slides rearward in response to combustion gas pressures provided by the gas tube of FIG. 1, to unload a fired cartridge. A fresh cartridge is loaded in the breech as the bolt carrier 208 is subsequently returned its initial pre-firing position by spring pressure. In the conventional AR-15,the action spring provides this pressure. The action guide 210 replaces the buffer assembly of the conventional AR-15 rifle of FIG. 1. A forward end 211 of the front link 205 is pivotally attached to the action guide 210 with a front pivot pin 212. A rear end 213 of the front link 205 is pivotally coupled to the rear link 206 via a middle pivot pin 214, which also functions as a front torsion spring mandrel. The rear link 206, in turn, is pivotally coupled to the rear of the action tube 201 via a stationary rear pivot pin 215, which also functions as a rear torsion spring mandrel. A front torsion spring 401 (shown in FIG. 4) wraps around the middle pivot pin 213. One end of the front torsion spring is downwardly biased against a first retaining groove 2l6 that is machined into a forward portion of the rear link 206, while the opposite end of the front torsion spring is downwardly biased through a torsion spring guide hole 217, thereby exerting a force which opposes downward hinging of the toggle 204. One end of a rear torsion spring 218, which is wrapped around the rear third pivot pin 213, is downwardly biased against a second retaining groove 219 machined into a rear portion of the rear link 206, while the opposite end of thereof is biased against the buttplate 220, thereby exerting an additional force which opposes downward hinging of the toggle 204 and forces the forward end 209 of the action guide 210 against the rear end of the bolt carrier 208. It is this spring force provided by the front torsion spring 401 and the rear torsion spring 218 that return the bolt carrier 208 to its initial position as a fresh round is loaded in the breech of the rifle 200.

Referring now specifically to FIG. 1, prior to firing the rifle, a line drawn between the axes of the front pivot pin 212 and the middle pivot pin 213 makes an obtuse angle of between about 177 and 178 degrees with a line drawn between the axes of the middle pivot pin 213 and the rear pivot pin 215. This obtuse angle represents the pre-discharge configuration of the toggle 204. If the two lines formed a straight angle, the toggle 204 would be unable to hinge downwardly upon firing, thereby preventing the spent cartridge ejection and fresh cartridge reload system from functioning. The 2 to 3 degree offset and the inertia of the toggle components provides maximum resistance against hinging the moment firing occurs when combustion gas pressures and opposite and equal reaction forces are at their peak.

Referring now specifically to FIG. 2, when combustion gas pressures are initially applied against both the front end 221 of the bolt carrier 208 through the gas tube of FIG. 1, the toggle 204 begins to hinge downwardly. The magnitude of the pressure remains relatively constant from the time the projectile passes the gas tube inlet in the barrel until the projectile leaves the barrel. As the toggle angle becomes less obtuse, increasingly greater mechanical advantage is applied against the spring forces exerted by the front and rear torsion springs 401 and 218, respectively. However, at the same time that the mechanical advantage is increasing, the anti-hinging force jointly applied by the middle and rear torsion springs is increasing as the springs are wound even tighter. As the projectile leaves the barrel, combustion gas pressures drop rapidly. Spring constants of the front and rear torsion springs, the obtuse angle, and the lengths of the middle and rear links (205 and 206, respectively) are selected so that are appropriate for the cartridges that are to be fired, in terms of combustion gas pressures generated by the exploding charge and the weight of the projectile. It will be noted in FIGS. 1 and 2 that the toggle hinges downwardly within the buttstock 222. A hollow cavity (not shown) within the buttstock 222 is sized to accommodate such movement. An action bumper 223 limits rearward travel of the action guide 210, which in turn, limits the amount of hinged movement of the toggle 204 that is both downward and rearward.

Referring now to FIG. 5, the new first embodiment hypervelocity rifle 200 of FIGS. 1, 2 and 3 is seen in an isometric view, minus the buttstock 222 and buttplate 220. In this view, the magazine insertion opening 501 can be clearly seen. A magazine (see FIG. 1) containing multiple cartridges can be inserted within the opening 501.

Referring now to FIG. 6, a second embodiment 600 of the new hypervelocity rifle has an action that is similar to that of the first embodiment of FIGS. 2, 3 and 4, with the exception that the front and rear torsion springs 401 and 217, respectively, are replaced by a stiffer single rear torsion spring 601, the tension of which can be adjusted without disassembly of the rifle 600. Alternatively, an unadjustable front torsion spring 401 can be used in combination with an adjustable rear torsion spring 601.

Referring now to FIG. 7, the rear pivot assembly has an end cap 701 that can be removed in order to adjust the tension of the rear torsion spring 601. Spring tension can be increased or decreased by rotating the cap. An adjustment disc (not shown), which fits within the pivot housing 702, can be rotated to a desired position and locked into place with a ratchet, a threaded fastener, or other suitable locking device.

As is was determined that the torsion springs of the first and third embodiment rifles of FIGS. 2 and 6 had a lifespan of only about 300 cycles due to metal fatigue, it was determined that a coil spring would provide a greatly enhanced useful life and greater reliability in the field. The coil spring version of the rifles of FIGS. 2 and 6 is shown in FIGS. 8 through 12.

Referring now to FIG. 8, a third embodiment spring-biased, toggle-action rifle 800 is shown prior to firing. The coil spring is mounted above the toggle. The rear link incorporates an extension lever having a rounded end. The rounded end operates on a sliding buffer which is biased against the coil spring. Thus, as the toggle transitions from a nearly straight configuration to a folded or toggled configuration during recoil of the weapon, the extension lever operates against the rear end of the sliding buffer to compress the coil spring.

Referring now to FIGS. 9, 10, 11, and 12, the third embodiment spring-biased, toggle-action rifle 800 is shown after firing, with the toggle at the final recoil position. 

1. A bolt-action firearm comprising: a frame; a butt-stock attached to a rear portion of said frame; a hollow barrel having a firing chamber; a bolt movable in said frame axially to and from the firing chamber of said barrel; a coil spring mounted in a generally horizontal position within a chamber affixed to said frame; a buffer slidable within said chamber biased against said coil spring; a toggle comprising a pair of hingeably coupled front and rear links, a foremost end of said front link being pivotally coupled to said bolt and a rear most end of said rear link pivotally coupled to said frame and incorporating an extension lever having a rounded end which operates against said buffer to compress said coil spring when the front and rear links are toggled in a downward direction when the weapon is fired and the bolt is driven rearward. 